Ms3 dominant genetic male sterility for wheat improvement with molecular breeding

<p>Genetic dominant male sterility (DMS) has not been widely used as a breeding tool in wheat (<i>Triticum aestivum</i> L.), although DMS-facilitated backcross, mass selection, half-sib selection, and S₁ family recurrent selection strategies have been described, and <i>Ms2-</i>facilitated recurrent selection has been used in China. Our objective was to revisit these strategies using the tools of molecular breeding. Development of a mechanism for seedling identification of sterile progeny was a key component of designing practical DMS-facilitated molecular breeding systems. The DMS gene <i>Ms3</i> was previously localized to the centromeric region of chromosome 5A. The centromeric location is an advantage because recombination rates are very low. Once identified, a broadly informative marker would reliably predict the male-sterile phenotype. A set of 429 hybrids incorporating <i>Ms3</i> were constructed, both within US hard winter wheats, and between these winter wheats and Asian spring wheats. Association of the male-sterile phenotype with those polymorphic DNA sequence tags that localized to chromosome 5A was tested using case-control association analysis. Two highly significant (logarithm of odds [LOD] &gt; 30) single nucleotide polymorphism (SNP)–trait associations were obtained. One SNP was developed into a highly sensitive, reliable molecular marker for the <i>Ms3</i>-associated male-sterile. Previously described breeding strategies using DMS were updated for trait-targeted marker-assisted backcrossing and gene pyramiding, S₁ recurrent selection, and early-generation genomic selection. Application of DMS to association mapping, with the particular use case of the multiparent advanced generation intercross population, is also described.</p>